(1) Field of the Invention
The present invention relates to a multiplex writing implement, and more specifically to a multiplex writing implement having at least two writing elements such as a mechanical pencil and a ball-point pen etc., which can be used selectively and further including a stick-shaped element such as an eraser etc., and a mechanism for delivering the stick-shaped element.
(2) Description of the Related Art
Various kinds of multiplex writing implements have been proposed up to now, and the basic structure for projecting and retracting a mechanical pencil refill or a ball-point pen refill as a writing element relative to the barrel body comprises a front barrel accommodating at least front end portions of the writing elements, a middle barrel accommodating the remaining portions of the writing elements, a rear barrel that is rotatable relative to the middle barrel, and a cylindrical cam which integrally moves with the rear barrel and has a shape enabling any one of the writing elements to project out of the front end of the barrel and the other writing elements to retract in accordance with the rotated direction of the rear barrel. Projection or retraction of any one of the writing elements can be performed by holding the front or middle barrel with the thumb and fingers of one hand and rotating clockwise or counter-clockwise, as required, the rear barrel with the thumb and fingers of the other hand.
The multiplex writing implement of this kind itself has a more complicated structure as compared to the single purpose writing implement consisting of a sole mechanical pencil refill or a sole ball-point pen refill. Further, in recent years, such writing implements of a complicated structure have been additionally equipped on the rear end thereof with a mechanism for delivering a stick-shaped element such as an eraser etc. For this reason, the multiplex writing implements tend to be further complicated in structure, and development of multiplex writing implements has been earnestly desired which have as simple a structure as possible and enable the storage and control of components before assembling to be further simplified.